Preparation of organic silicon compounds



Patented Aug. 21, 1951 PREPARATION OF ORGANIC BILIOON COlflOUNDS Nicholas D. Cheronis, Chicm. Ill.

No Drawing. Application August "I, 1947, Serial No. 767,331

10 Claims. (0!. 260-4483) This invention relates to silicon polymers, and more particularly to new methods of reacting organic silicon halides with ammonia or substituted amines.

An object 01' my invention is the production 01' ammonolyzed silicone compounds by reacting an aliphatic silicon halide with liquid ammonia or a liquid .substituted amine.

Another object of my invention is the production oi ammonolyzed silicon compounds by reacting an aromatic silicon halide with liquid ammonia or a liquid substituted amine.

A further object 01' my invention is the production 01' a polymerized silicon resin containing NH: and/or NH groups directly linked to the silicon atom, with the silicon atoms interconnected by N ro p Still another obiect of my invention is an ammonolyzed silicon resin capable oi rapid but controllable polymerization.

Other objects and advantages of my invention will become apparent as the following description or my invention proceeds.

U. 8. Patent application Serial No. 616,475, Nicholas D. Cheronis, "Silicon Polymers," filed September 14, 1945 (now abandoned in i'avor oi continuation-impart application Serial No. 72,548, Nicholas D. Cheronis, Polymeric Resinous Products Containing Repeating Units 01' Silicon Linked to Nitrogen and Process for Making Same. filed January 24, 1949), and application Serial No. 643.494, Nicholas D. Cheronis and Edwin L. Gustus, "Preparation of Polymers," filed January 25, 1946, describe methods or ammonolyzing organic silicon halides; application Serial No. 613.009, Nicholas D. Cheronis, Water-Resistant Leather," filed August 27, 1945 (now abandoned in favor of continuation-in-part application Serial No. 56,663, Nicholas D. Cheronis. Resin-impregnated Water-Resistant Leather, filed October 26, 1949), and application Serial No. 643,493, Nicholas D. Cheronis and Edwin W. Newbury, "Leather Treatment/f describe the application of hydrolyzed and/or ammonolyzed organic silicon halides to leather. The present invention deals with novel methods of making ammonolyzed organic silicon halides of the general structure disclosed in these applications.

A silicone resin is generally understood to be a polymeric compound corresponding to the type formula 1 a a no-dq-o-sIm-o-si-on i i? i 2 where R stands for an aliphatic or aromatic radical, and where Y stands for an aliphatic or aromatic radical or a hydroxyl group. Such a resin is formed by the condensation of organosilicon hydroxy compounds of the type formula wherein n does not exceed 2, which in turn are the hydrolysis products or an organic halosilane oi the type formula RnSiHiili-n wherein it also does not exceed 2. Cross linkages within the polymer group may reduce or almost entirely eliminate the hydroxyl groups and replace them by roups- I! organic halosilanes are ammonolyzed in accordance with my invention, and polymerized, or-

ganic polymers of the type formula are formed, wherein silicon atoms are interconnected by NH groups and tree silicon valences at either end of the polymeric group have NH: groups attached thereto. The starting material for such compounds are again the organic halosiianes oi the type iormula RnSlHB-lin I have discovered that an organic halosilane may be converted into a corresponding ammonolyzed compound by dissolving it in an organic solvent which is inert towards the organic halcsilane (i. e., does not react with it) and reacting it with liquid ammonia (unsubstituted or substituted) in the absence of water or moisture and under conditions about to be described. and permitting the resulting amino silanes to polymerize to the desired degree. Suitable aliphatic solvents are ethers, such as ethyl ether or propyl ether, while suitable aromatic solvents are toluene or xylene. Organic halosilanes suitable in the reaction are, for instance, mono-, or trichlorides, bromides, iodides or fluorides of a silane substituted with respectively 3, 2, or 1 alkyl or aryl group. If more than one organic group is attached to the silicon atom, such organic groups need not be identical. Suitable as ammonolyzing agents, in addition to liquid ammonia, are such compounds as ammonium carbamate and primary alkyl or aryl amines which are liquid at the low temperature at which the reaction takes place, e. g., methylamine (boiling point 6.5' C.) ethylamine (boiling point -l6.6 C.), propylamine, n-butylamine, iso-butylamine, benzylamine, naphthylamine, ethylene diamine, hexamethylene diamine. hexamethylene tetramine, phenylene diamine, propenvlamine, and other related compounds. In fact, all nitrogen compounds containing at least two replaceable hydrogen atoms directly bonded to a nitrogen atom are suitable for reaction with the silicon compound, so long as care is taken not to introduce any groups into the compound which will prevent polymerization by steric hindrance. To obtain polymerizable compounds, a dior tri-halogenated organosilane is selected as starting material, inasmuch as hydrolyzed or ammonolyzed monochloro-organosilanes form only dimers.

In addition to methyl trichlorosilane, dimethyl dichlorosilane, diethyl dichlorosilane, ethyl trichlorosilane, ethyl tribromosilane. ethyl tri-iodo silane. e hyl trifluorosilane, ethyl dichloro monofiuorosilane, propyl tribromosilane, butyl triiodo silane, n-propyl trichlorosilane, dipropyl dichlorosilane, iso-propyl trichlcrosilane, n-butyl trichlorosilane, iso-butyl trichlorosilane. isoamyl trichlorosilane, benzyl trichlorosilane, naphthyl trichlorosilane, amyl dichlorosilane, propenyl trichlorosilane, phenyl trichlorosilane, diphenyl dichlorosilane, methyl ethyl dichloro silane, phenyl methyl dichlorosilane, dibenzyl dichlorosilane. p-chlorophenyl silicon trichloride, n-hexyl trichlorosilane, cyclohexyl trichlorosilane, dicyclohexyl dichlorosilane, di-isobutyl dichlorosilane, paratolyl trichlorosilane, di-paratolyl dichlorosilane, para-styryl trichlorosilane, ethynyl trichlorosilane, which are mono-alkyl, di-alkyl, alkyl-aryl and di-aryl halosilanes whose ammonolysis is described in the above-enumerated earlier applications, I find that such organic halosilanes as allyl trichlorosilane, and di-allyl dlchlorcsilane (halosilanes containing unsaturated alkyl groups), n-dodecyl trichlorosilane (a long-chain alkyl chlorosilane), p-anisyl trichlorosilane, and para-ethoxy phenyl trichlorosilanes (chlorosilanes containing aromatic or!- substituted groups) can be ammonolyzed and polymerized in accordance with the present invention.

One preferred example of ammonolysis and polymerization in accordance with the present invention will now be given by way of illustration:

Example A bucket, equipped with a stirrer, is placed in a Dry Ice bath. Two liters of dry other are placed into the bucket and stirred until the temperature is about 40 C. One liter of liquid ammonia is now placed into the vessel. and about 1000 grams of an organic chlorosilane (e. g., diethyl-dichlorosilanel dissolved in 1500 cc. of dry ether are slowly added to the stirred system in a controlled stream which is adjusted to maintain the temperature of the reaction at or below -40 C. At the same time, an excess 0! liquid ammonia, say 3 liters, is added in a controlled stream to maintain the temperature of the reaction at or below 40 C. An excess of ether, of the order of 3 liters, is added to the system towards the end of the reaction to dissolve the silicon compounds and prevent their gelation. Ammonolysis takes place in the system in accordance with the formula The end product or reaction mixture is removed from the bucket, filtered to remove the ammonium chloride and washed repeatedly, e. g., four times. with ether. To stabilize the solution, most or all of the ether is removed under reduced pressure and/or at an elevated temperature (e. g., 60 to C.) and replaced by a hydrocarbon solvent which is inert towards the formed organic silicon amine (silamine). Suitable hydrocarbon solvents are, for example, anhydrous xylene, toluene, hexane, or a cycloparamn; carbon tetrachloride is also suitable, though not as favorable a solvent medium as the before-mentioned solvents. The yield is 850-900 grams containing 45-50% solids. which is -95% of the theoretical yield.

All the organic halosilanes mentioned in the specification may be ammonolyzed in accordance with this example. Absence of water during the reaction is essential to avoid undesired hydrolysis.

It will be understood that the corresponding fluoro-. bromoand iodo-silanes may be substituted for the chlorosilanes mentioned in the above example.

Mixtures of fully substituted organic silicon monoamines, diamines and triamines can be so adjusted that the resin resulting from their poly merization possesses any desired properties with regard to hardness or tackiness. Thus. an organic silicon triamine polymerized by itself will yield a harder and more brittle film than a mixture of polymerized triamine with a diamine or monoamine. The resins are tough and flexible and thus are eminently adapted to the impregnation of leather, textiles, papers and other flexible materials, and they possess favorable adhesive properties with regard to metal (e. g., steel).

assae'n to carry out the reaction at temperatures substantially below room temperature; the most favorable temperature differs with each individual ammonolyzing nitrogen compound, and particularly is a function of its boiling point. In the case 01' liquid ammonia. the reaction, temperature must be maintained well below 0.. and preferably as low as -40 C.

Polymerization of the organic silamines made in accordance with my process takes place at temperatures somewhat above room temperature, in the neighborhood 01' 60 0. Even at room temperature spontaneous polymerization takes place upon exposure to the air for one or two days. Polymerization takes place by elimination of ammonia groups which separate out in gaseous form and may be collected by appropriate measures, e. g., in a hood. The polymerization, or rather condensation, of an organic diaminosubstituted silicon monomer may be represented by the formula In the condensation of a triamino-substituted organic silicon monomer, cross linkages by NH groups are formed:

Monoamino-substituted organic silicon monomers form only dimers:

213.381 (NI-I2) RaS1,NH.SiR3+NIhT A chief advantage of silamine condensation as compared with the condensation of chlorosilancs is the absence of hydrochloric acid as a byproduct of the condensation; hydrochloric acid is injurious to textiles and other materials which, however, can be safely coated with a silamine polymerized thereon in situ.

The terms "polymerization" and "condensation," as well as polymerize and "condense, are used as synonyms throughout the specification and claims.

I do not wish to limit myself to the foregoing specific example of a method to prepare organic silamines in accordance with my invention, nor to any particular proportions of reactants, speeds of reaction, etc. Modifications of my liquid ammonia ammonolysis of organosilicon halides in the absence of water or moisture, within the spirit of my invention, will readily occur to an expert skilled in the art 01' synthesizing organosilicon compounds. Likewise, other sllamines than those specifically enumerated in the foregoing specification and example, e. g., homologues oi the named compounds, may be prepared in accordance with my disclosure and thus are within the scope of my invention. I therefore desire to limit my invention only by the appended claims.

I claim:

1. The method of ammonolyzing a mono-organic silicon tri-halide, comprising dissolving said organic silicon halide in an organic solvent inert toward said organic silicon halide, reacting said dissolved organic silicon halide with an emmonolyzing liquid nitrogen compound selected from the class consisting of liquid ammonia and liquid primary amine wherein the amino group is the sole functional group, by simultaneously introducing controlled streams of said dissolved organic silicon halide and of an excess oi said liquid nitrogen compound into a reaction vessel at a temperature below. room temperature and in the absence of water, and maintaining the temperature of the reaction by adjusting the reactant supply so as to maintain an excess oi said ammonolyzing liquid nitrogen compound until said reaction is substantially complete.

2. The method 01 ammonolyzing a mono-organic silicon tri-halide, comprising dissolving said organic silicon halide in an ether inert toward said organic silicon halide, reacting said dissolved organic silicon halide with an ammonolyzing liquid nitrogen compound selected from the class consisting of liquid ammonia and liquid primary amine wherein the amino group is the sole functional group, by simultaneously introducing controlled streams 01 said dissolved organic silicon halide and of an excess 01' said liquid nitrogen compound into a reaction vessel at a temperature below room temperature and in the absence of water. and maintaining the temperature of the reaction by adjusting the reactant supply so as to maintain an excess 01 said ammonolyzing liquid nitrogen compound until said reaction is substantially complete.

3. The method of ammonolyzing a mono-organic silicon tri-halide, comprising dissolving said organic silicon halide in an ether inert toward said organic silicon halide, reacting said dissolved organic silicon halide with an ammonolyzing liquid nitrogen compound selected from the class consisting oi liquid ammonia and liquid primary amine wherein the amino group is the sole functional group, by simultaneously introducing controlled streams of said dissolved organic silicon halide and of an excess of said liquid nitrogen compound into a reaction vessel at a temperature of the order oi -40 C. and in the absence or water, and maintaining the temperature or the reaction by adjusting the reactant supply so as to maintain an excess 01 said ammonolyzing liquid nitrogen compound until said reaction is substantially complete.

4. The method 01' ammonolyzing a mono-organic silicon tri-halide, comprising dissolving said organic silicon halide in a hydrocarbon solvent inert toward said organic silicon halide, reacting said dissolved organic silicon halide with an ammonolyzing liquid nitrogen compound selected from the class consisting of liquid ammonia and liquid primary amine wherein the amino group is the sole functional group, by simultaneously introducing controlled streams of said dissolved organic silicon halide and of an excess of said liquid nitrogen compound into a reaction vessel at a temperature below room temperature and in the absence 01 water, and maintaining the temperature of the reaction by adjusting the reactant supply so as to maintain an excess 0! said ammonolyzing liquid nitrogen compound until said reaction is substantially complete.

5. The method of ammonolyzing a mono-organic aromatic silicon tri-halide, comprising dissolving said organic silicon halide in an organic silicon halide in a hydrocarbon solvent inert toward said organic silicon halide, reacting said dissolved organic silicon halide with an ammonolyzing liquid nitrogen compound selected from the class consisting of liquid ammonia and liquid primary amine wherein the amino group is the sole functional group, by simultaneously introducing controlled streams of said dissolved organic silicon halide and of an excess of said liquid nitrogen compound into a reaction vessel at a temperature below room temperature and in the absence of water. and maintaining the temperature of the reaction by adjusting the reactant supply so as to maintain an excess or said ammonolyzing liquid nitrogen compound until said reaction is substantially complete.

8. The method of ammonolyzing a mono-organic silicon tri-halide, comprising dissolving said organic silicon halide in an aromatic solvent inert toward said organic silicon halide. reacting said dissolved organic silicon halide with an ammonolyzing liquid nitrogen compound selected from the class consisting of liquid ammonia and liquid primary amine wherein the amino group is the sole functional group, by simultaneously introducing controlled streams of said dissolved organic silicon halide and of an excess of said liquid nitrogen compound into a reaction vessel at a temperature below room temperature and in the absence of water, and maintaining the temperature 01' the reaction by adjusting the reactant supply so as to maintain an excess said ammonolyzing liquid nitrogen compound until said reaction is substantially complete.

'7. The method of ammonolyzing a mono-organic silicon tri-halide. comprising dissolving said organic silicon halide in an organic solvent inert toward said organic silicon halide, reacting said dissolved organic silicon halide with an ammonolyzing liquid nitrogen compound selected from the class consisting of liquid ammonia and liquid primary amine wherein the amino group is the sole functional group, by simultaneously introducing controlled streams of said dissolved organic silicon halide and of an excess 01' said liquid nitrogen compound into a reaction vessel in the absence oi water, at a temperature below room temperature and below the boiling point of said ammonolyzing agent, and maintaining the reaction at said temperature by adjusting the reactant supply so as to maintain an excess of said ammonolyzing liquid nitrogen compound un til said reaction is substantially complete.

8. The method or ammonolyzing a mono-organic silicon tri-halide, comprising dissolving said organic silicon halide in an organic solvent inert toward said organic silicon halide, reacting said dissolved organic silicon halide with liquid ammonia in the absence of water, by simultaneously introducing controlled streams of said dissolved organic silicon halide and of an excess 01' said liquid ammonia into a reaction vessel at a temperature of the order or 4il 0., and maintaining the reaction at a temperature or the order of -40 C. by adjusting the reactant supply so as to maintain an excess of liquid ammonia until said reaction is substantially complete.

9. The method of ammonolyzing a mono-alkyl silicon tri-halide. comprising slowly adding said mono-alkyl silicon tri-halide to liquid ammonia at a temperature below the boiling point of ammonia. simultaneously slowly adding an excess oi. additional liquid ammonia at said temperature, maintaining the reaction product in solution in an inert organic solvent, and separating the reaction product from the excess reactants and from the ammonium halide also formed.

10. The method according to claim 9, wherein said inert organic solvent is ether.

NICHOLAS D. CHERONIS.

REFERENCES CITED The following references are of record in the ills of this patent:

UNITED STATES PATENTS Name Date Haber Feb. 22, 1949 OTHER REFERENCES Number 

1. THE METHOD OF AMMONOLYZING A MONO-ORGANIC SILICON TRI-HALIDE, COMPRISING DISSOLVING SAID ORGANIC SILICON HALIDE IN AN ORGANIC SOLVENT INERT TOWARD SAID ORGANIC SILICON HALIDE, REACTING SAID DISSOLVED ORGANIC SILICON HALIDE WITH AN AMMONOLYZING LIQUID NITROGEN COMPOUND SELECTED FROM THE CLASS CONSISTING OF LIQUID AMMONIA AND LIQUID PRIMARY AMINE WHEREIN THE AMINO GROUP IS THE SOLE FUNCTIONAL GROUP, BY SIMULTANEOUSLY INTRODUCING CONTROLLED STREAMS OF SAID DISSOLVED ORGANIC SILICON HALIDE AND OF AN EXCESS OF SAID LIQUID NITROGEN COMPOUND INTO A REACTION VESSEL AT A TEMPERATURE BELOW ROOM TEMPERATURE AND IN THE ABSENCE OF WATER, AND MAINTAINING THE TEMPERATURE OF THE REACTION BY ADJUSTING THE REACTANT SUPPLY SO AS TO MAINTAIN AN EXCESS OF SAID AMMONOLYZING LIQUID NITROGEN COMPOUND UNTIL SAID REACTION IS SUBSTANTIALLY COMPLETE. 